SU1539050A1 - Method of deformation broaching - Google Patents

Abstract

The invention relates to metal working, in particular to the processing of plastic deformation holes. The purpose of the invention is to improve the processing accuracy of long thin-walled parts by fixing the geometry of the cross section of the material in the non-contact zone. For machining the hole of the part, a broach is used, between the conical and cylindrical parts of the last deforming element of which an additional curvilinear section is formed, which is described by the equation R _y = R _to + TGΑ ^. Z - TGΑ / 2L ₁ ^. Z ³ + TGΑ / 8L ^3. Z ⁴ , where R _y is the current value of the radius forming the outer surface of the additional section

R _to - the radius of the larger base of the conical section

α - the angle of inclination of the generatrix of the conical part

Z - the axial coordinate of the additional area

L ₁ is the length of the additional section, and the length of the additional section is determined by the dependence @ L ₁ = 0.611 T ° ^{, 54.} R ° ^{, 46} , where T ₀ , R ₀ is the wall thickness and the radius of the hole of the workpiece. At the same time, the radius of the cylindrical part of the last deforming element exceeds the radius of the larger base of the conical part and is less than the maximum radius of the additional section by the amount of elastic recovery of the workpiece. As a result, when the working parts of the tool interact with the machined surface, a moment is created that prevents the workpiece from bending, i.e. the part is being processed during processing. 1 il.

Description

The invention relates to metalworking, in particular to the processing of holes by plastic deformation in machine-building enterprises.

The purpose of the invention is to improve the accuracy of processing of long thin-walled parts by fixing the geometry of the material flow in the non-contact (zone.

The drawing shows a diagram of the implementation of the method.

The method is implemented using an extension 1 consisting of a rod 2, at one end of which a shank 3 is made. On the rod 2 deforming elements 4 and 5 are rigidly interconnected. In the last deforming element 5 between the conical part 6 and the cylindrical part 7 whose length is greater than the length

out-of-order zone and less than the length of the part, an additional curvature-section 8 is made, which is formed by the equation

rrk + lЈdz

tgof

Where

Have

year

s

212 z + 81з2

(one)

d

the current value of the radius forming the outer surface of the additional area; the angle of inclination of the generatrix of the conical part; the axial coordinate of the additional plot; radius of the larger base of the conical section; additional site plot,

The cnchcha of the additional section 8 depends on the size of the workpiece and is determined by the dependence

0.6

I

Oh Ј4

I, 09611t0

(2)

Where

t g - - o L o

wall thickness and radius Q of the workpiece hole. The radius of the cylindrical part 7 exceeds the larger radius of the conical part and is equal to the difference between the maximum radius of the additional section 8 and elastic recovery A. The maximum radius of section 8 is determined from the expression (1) when

r.

Elastic recovery d after the distribution of the workpiece moss to determine the dependence

6, -, r „, .o, f“

gkb, - rD about. "

KVs L °

(four)

where E is the modulus of elasticity of the 1st kind of material being processed; & 1 stress intensity, determined by the flow curve, corresponding to the relative total strain 1; sleeves on average diameter, the value of which is determined by the dependence 2r + t

I;

2r0 + t0

 where r, t is the radius of the hole and the wall thickness of the workpiece.

Thus, the radius of the cylindrical part 7 is determined from the expression

, G0, 0, US

. + S / Stgall, - - () °

When a load is applied to the shank ™ 3, the broach moves through the machined, opening of the workpiece 9, and the deforming elements 4 and 5 deform the workpiece 9. When the element 5 deforms, at the point of transition of the working cone 6 into the additional section 8, a non-contact

JQ zone, the plastic area of which exactly corresponds to the shape and size of the additional section 8. Therefore, the flow geometry of the material in this zone will be strictly determined by the shape

 tool that allows reducing such types of errors as corsetting, barrelness, ovality. i

When reaching the maximum of the non-contact zone corresponding to the maximum

At the maximum radius of the additional section, the plastic deformation of the material is stopped and the elastic recovery zone begins. Since the radius of the cylindrical part 7 is higher than

25 em is the radius of the larger base of the conical part 6 and is equal to the difference between the maximum radius of the part in the non-contact zone and the elastic recovery of the part, and the length of the cylindrical part

30 is greater than the length of the non-contact zone, the part material at the time of elastic recovery in all cases (breakdown or shrinkage of the hole) contacts the surface of the cylindrical

35 of the section 7. When the long cylindrical part 7 interacts with the surface of the workpiece 9, a moment is created that prevents the curvature. details i.e. the part is governed by the distribution process. This improves the accuracy of the part by reducing this type of error as the curvature of the axis.

To compare the proposed method with the prototype, the following experiments were carried out. Handle wave pipe preforms of brass L63 with dimensions BxtxL 48x3x1100. The pulling according to the prototype is carried out by a stitch, on the rod of which two deforming elements are placed with a working cone and with a diameter of 43.5 and 45 mm cylindrical parts. The length of the cylindrical part of the last deforming element is longer than the non-contact zone and less than the length of the part and is 50 mm.

(5) Pulling in accordance with the proposed method is also carried out

55

tight with two deforming elements. The diameter of the cylindrical part of the first element is 43.5 mm. The diameter of the larger base of the working cone of the second element is 45 mm. The second deforming element is provided with an additional curvilinear section, which is positioned between the conical and cylindrical parts of this element. Forming of this section is described by equation (1), and its length is determined by dependence (2) and is equal to 4.5 mm. The maximum radius is the complementary of which consists of a working cone and a cylindrical part having a length greater than the noncontact deformation zone and less than the length of the workpiece, characterized in that, in order to improve the accuracy of processing long thin-walled parts by fixing the flow geometry of the metal in non-contact the zone, the processing of the part is carried out by a flow path, in which between the working cone and the cylindrical part of the last deforming element is made the pre-generating which is described by the equation

g r + tPc (z-za + -S-, rK + t: gc z 712z +, 3

21V

813

74

Z t

Where

rs

The body section is determined by the dependence-15 polar curved section, bridges (3) and is equal to 22.69 mm. The elastic recovery per hole radius is determined by the relation (4). In this case, it is equal to 08 mm. The radius of the cylindrical part of the last element is determined by the dependence (5) and it is equal to 22.61 mm. Each of the methods involves 73 blanks. After deformation of the workpieces, the change in diameter of the .-. 25 along the length of the part 6, the curvature of the axis of the part at, ovality y are measured. The experimental data are tabulated.

The results indicate that the use of the proposed method makes it possible to significantly reduce such types of error as the change in diameter along the length of the part, ovality, the curvature of the axis of the part.

The application of the proposed method makes it possible to improve by 2-3 times the accuracy of long thin-walled parts treated with deforming broaching.

the current value of the radius forming the outer surface of the additional area; the radius of the larger base of the conical section; - the angle of inclination of the generatrix of the conic section; the axial coordinate of the additional plot; additional section length

and the length of the additional section is determined by the dependency

z „Z

one -

 l

35

I, 0.611t0 where t and g „О, 0.4t

 about

t0 and r0 - wall thickness and radius

billet holes; the radius of the cylindrical part of the last deforming element exceeds the radius of the larger base of the conical part and is less than the maximum radius of the additional section by the amount of elastic recovery of the bore hole after drawing

Claims (1)

Invention Formula A deforming pulling method in which the part is machined with a rigidly connected bore the last of which consists of a working cone and a cylindrical part having a length greater than the length of the non-contact deformation zone and less than the length of the workpiece, characterized in that, to improve the accuracy of processing long thin-walled parts by fixing the geometry of the metal flow in the non-contact zone, the parts are carried out by a draw, in which between the working cone and the cylindrical part of the last deforming element is made before forming which is described by the equation the polar curved section, g r + tPc (z-za + -S-, rK + t: gc z 712z +, 3 21V 813 74 Z t I'm a curvilinear body de rs solder curvilinear section the current value of the radius forming the outer surface of the additional area; the radius of the larger base of the conical section; - the angle of inclination of the generatrix of the conic section; the axial coordinate of the additional plot; additional section length and the length of the additional section is dependent on z „Z one -  l I, 0.611t0 where t and g „О, 0.4t  about t0 and r0 - wall thickness and radius billet holes; the radius of the cylindrical part of the last deforming element exceeds the radius of the larger base of the conical part and is less than the maximum radius of the additional section by the amount of elastic recovery of the bore hole after drawing f4 o f-e